Since Deuteronomy is essentially a second iteration of the religious laws that had been established by the leaders of the Israelites, we are bound to see some repetition of themes. It might seem that the Israelites had to be told something several times before they got it (if they ever got it), which is human nature to a certain extent. It's more likely that the same oral tradition was being transcribed by many different people in different places over a long period of time, the end result being several distinct versions of that oral tradition. As these traditions were developed, it was possible to clarify things, answer questions, revise things that didn't make sense -- allow the religious text to grow with the culture. Once it was codified (or canonized), it became easy to believe that the religious text was complete for all time and needed no further clarification or revision. Human culture has changed time and time again since -- church cultures have even changed many times over -- while the Bible has become something of a relic from an ever more distant time and culture. It becomes increasingly difficult to draw meaningful spiritual value from some scriptural passages without simply using them as a template for how not to behave.
Case in point: Deuteronomy 12-13. There are several reasons why these chapters require revision. Although some will immediately admit that what is recorded here has already been revised in the New Testament, that doesn't explain why people can easily dismiss one problematic Old Testament passage and cling to others that are equally offensive of culturally inappropriate. It's informative for Christians to see how their religion developed, but unfortunately, it's not a stretch for twenty-first century Christians to extrapolate misguided lessons from taking these passages at face-value. In these chapters, the Israelites are told to establish one place to make all of their sacrifices to their god, and they are commanded to destroy all the evidence of other gods.
It's easy to see why folks would dismiss the bit about having one central place of genuine worship for the whole religion. Even though there are provisions for what to do if you live too far away to make your sacrifices in person, the implication is that there is one geographical location where true connection to God can take place. With all of the denominations and churches that exist in our world, it would be a real feat to get everyone who claimed the label of "Christian" to go to one specific place to have a time of authentic spiritual connection, but it's also easy to see that this rule is just for the Jews. Except that the Jewish faith no longer strictly adheres to the same religious laws that are dictated in the Old Testament either. I don't really have a problem with discarding or rewriting any of this. My point is that if this passage is so clearly inappropriate for modern Christianity, why is so difficult to see that much of the Old Testament falls into the same category? If it's obvious that this is meant for a specific culture at a specific time, why do people cling to other similar passages as if they were eternally valid?
I actually know the answer, at least in part. Having one central place of worship is practically untenable. Exceptions had to be made just because of the practical realities of life. The fact that people who disagreed with the Church later broke away and formed their own sects based on their own divergent philosophies complicated things to the point where people cannot fathom a reasonable god expecting them to go to a specific appointed place for worship. For one thing, the sacrifices are supposedly unnecessary because of Jesus' one big sacrifice for once and all. (I happen to believe that the sacrifices are unnecessary for a different reason.) For another thing, there's no longer any fear attached to being separated from THE temple, because religious thought has evolved into belief in an omnipresent deity who is not constrained by geography or physical laws.
What people still fear, though, is other people's beliefs. The Israelites are told to destroy the sacred places and things of the people they encounter, and they're told to kill anyone who attempts to convince them to take part any any non-Israelite religious experience. Obviously this is one exception to the Ten Commandments, in which the Israelites were told not to murder other Israelites, which begs the question: What other exceptions might there be? At least it's plausible that the thought may occur to us if we were ancient Israelites. There can be only one reason for this drastic measure, and that reason is fear.
Many people disguise their fear behind aggression. Anger and violence are often a scary enough identity that we often don't have to deal with what we fear, although we do wind up dealing with the consequences of our anger and violence. The Israelite leaders were not altogether secure in their new endeavor, the society they were attempting to build was not at a securely established culture, and there were many threats from the traditions of other cultures around them. While they could have worked at deepening the beliefs of their culture to the extent that no other culture's practices would seem appealing, the easiest way to deal with those threats was to eliminate them. After all, the culture they were establishing was one of sacrifice in obedience to a vengeful and jealous god, and some of the religions around them probably seemed much more lenient by comparison. Merely villainizing people by calling them baby-killers might work for some Israelites, but someone would eventually get curious and figure out that there wasn't a whole lot of baby sacrificing going on. Better to just convince the Israelites to wipe out any trace of other religions and kill anybody who even suggested participating a little cultural exchange.
The genius move on the part of the Israelite leader was to pin these fears on the god they invented. "We don't want you to go around killing your brothers or children for merely suggesting checking out the church over the hillock, but God demands it of you. Our hands are tied here." Very clever. Maintaining a hold on society by sanctifying the murder of one's family doesn't seem like a long-term plan for success, but I'm sure that the Israelite leaders thought they could eradicate the threat of more appealing religions and cultures before Israelite-on-Israelite violence became a real problem. If we were to accept the existence of the Israelites' god, it would seem obvious that his vengeance and wrath toward these other religions was a reflection of some fear that his followers would be enticed away by more attractive gods. We've all seen similar behavior in angry people around us who were quite obviously afraid of not getting their way. Dispensing of superstition, though, it's even more plausible that the Israelite leaders were terrified that their society would fall apart and become subsumed into neighboring cultures if they didn't take drastic measures to ensure its survival.
Some Christian groups today sound very similar, specifically those toward the Conservative, Fundamentalist end of the spectrum. They often project an outward image of hostility, anger, and righteous indignation to hide their fear that if all ideas are given equal attention, their version of reality would not hold up against the competition. Except it isn't a competition unless you're trying to force other people to agree with you. Unlike the defunct ancient Israelite religion, Americans don't have the freedom to kill people for thinking something different from other folks. Everyone can believe what they want and practice their religion freely to the extent that it doesn't negatively impact the lives and well-being of other people (and animals) around them. We all have a set of general laws that we're expected to live within, but until your religious beliefs start informing how other people are allowed to behave, there generally aren't a lot of restrictions on belief.
Fear gets in the way. Whether it's fear that our religious beliefs will not be accepted, fear that someone will reject us personally, fear that we won't be considered smart enough, attractive enough, competent enough, or whatever the case may be, our fear creates the illusion of threats all around us. We don't have to accept that illusion. We have options aside from irrational fears. Another person's beliefs don't determine the value of our own beliefs. Another person's way of life is not a challenge to our own decisions and choices. If we are willing to accept that we are personally responsible for our own choices and actions, and we are willing to let other people be personally responsible for their own choices and actions, we really don't have a whole lot to fear. We can let go of angry and hostile masks and be our authentic selves, confident in our own beliefs and accepting of other people, even if their beliefs differ radically from our own.
When we fight so hard to defend our personal beliefs against imagined attacks, not only do we become exhausted, but we also stunt our own growth. When all of our time and energy goes toward being afraid and projecting anger -- or however we choose to project our fear -- we rob ourselves most of all. If we spent that time and energy on examining and understanding our own beliefs, other people's ideas wouldn't seem so threatening. If we spent that time and energy on deepening our own awareness of who we are, what nurtures us, what matters most to us, we could make a much greater impact on the world than anyone makes through angry rhetoric or hyper-inflated outrage.
Stop attacking the things that are different. Stop being afraid of people who think or believe differently from you. Look at your own beliefs and test them. If they have real value for you, nurture them in your own life without demanding that other people validate you. You have within you a deep sense of what is true, beneath the anger and the fear, beneath the contrived hatred and the unwillingness to see other people as equally human, at the core of who you are, there are a few things you know. People have value. For whatever reason you want to accept, human beings have value. You are at your core beautiful and creative, and that beauty and creativity is capable of doing more good in the world than any amount of hostility can ever achieve. Relax and let your beliefs be a foundation for how you will be in the world rather than a weapon to be used against it. Let your beliefs inform how you will honor yourself and other people and the world around you, not whether anyone is worthy of respect. When your beliefs become a justification for violence, you've slipped over into fear. And ultimately, your fear hurts you most of all. Start instead from the truth that people have value, and leave it to your beliefs to tell you why.